Sun's Network File System (NFS)
One of the first uses of distributed client/server computing was in
the realm of distributed file systems. In such an environment, there
are a number of client machines and one server (or a few); the server
stores the data on its disks, and clients request data through well-
formed protocol messages. Figure 47.1 depicts the basic setup.
As you can see from the (ugly) picture, the server has the disks;
the clients communicate through the network to access their directo-
ries and files on those disks.
Why do we bother with this arrangement? (i.e., why don't we just
let clients use their local disks?) Well, primarily this setup allows for
easy sharing of data across clients. Thus, if you access a file on one
machine (Client0) and then later use another (Client2), you will have
the same view of the file system. Your data is naturally shared across
these different machines. A secondary benefit is centralized admin-
istration; for example, backing up files can be done from the few
server machines instead of from the multitude of clients. Another
advantage could be security; having all servers in a locked machine
room prevents certain types of problems from arising.